Various ethylideneaminooxyacetic acids and their esters are generally known. For example, (.+-.)-isopropylideneaminooxypropionic acid is useful as a starting material for the preparation of 2-(2,4,5,7-tetra-nitrofluoren-9-ylideneaminooxy)propionic acid methyl esters; Org. Mag. Res., 20, pp. 145-150 (1982); propionic acid esters, including 2-[[(1-mono or dimethylethylidene)amino]oxy]-propanoic acid and its methyl ester are useful as intermediates for the production of diphenyl ether herbicides, U.S. Pat. No. 4,329,488 (European Patent Application 30,702); synthesis and analgesic, sedative and anticonvulsant properties of m-(trifluoromethyl)benzyl methyl ketone derivatives, including [[[1-methyl-2-[3-(trifluoromethyl)phenyl]ethylidene]amino]oxy]-acetic acid, have been explored, Chem Abstracts 77:139518h; and the synthesis and resolution of dl-alpha-(isopropylideneaminooxy)propionic acid are also known, Chem Abstracts 63:5523(b) (1965).
However, none of these publications recognize the class of compounds and compositions of the present invention which have a broad spectrum of herbicidal activity and which are herbicidal toward difficult to control weeds such as cocklebur, sicklepod, velvetleaf and nutsedge.